Effect of 7 days of chronic intermittent hypoxia (CIH) on mean arterial pressure (MAP) and heart rate (HR) during the light phase (left) and the normoxic dark phase (right). All rats were normoxic for 3 days of baseline (bs). Data shown for the light phase are mean pressures from 0800 to 1600 h during CIH (ih). Following CIH exposure, rats were allowed to recover for 3 days (p). Animals in subsequent experiments were killed on the morning following ih7. CON, control. *P < 0.05 vs. control; n = 6–8 rats.

Representative digital images of FosB/ΔFosB staining in CON rats (left) and rats exposed to CIH for 7 days (right). Depicted in order from top to bottom are: the OVLT, SFO, and the subcommissural MnPO. Each pair of CON and CIH images was adjusted for uniform brightness and contrast. Below the photomicrographs are the mean no. of FosB/ΔFosB-positive cells in the OVLT, SFO, MnPO, and SON. Scale bar = 50 μm; *P < 0.05 vs. CON; n = 6–8/group.

Neuroanatomical mapping of FosB/ΔFosB (filled triangles), DBH (open squares), and double-labeled (closed circles) cells to representative hindbrain sections of the caudal, subpostremal, and rostral NTS and ventrolateral medulla from a CON rat (A) and a 7-day CIH rat (B). Images are ordered caudal to rostral from left to right.